Import keys from filesystem. (#13056)

* Import keys, re-initialize KeyManager, re-scan vfs, re-populate game list.

* <.< spelling.

* Update based on feedback on #13047 and this PR

* Based on feedback: Don't delete existing files. There's legitimate reasons that someone may want to keep their retail keys and title key handling is resilient to mismatches.

* Update src/yuzu/main.cpp

Co-authored-by: Tobias <thm.frey@gmail.com>

* Remove translation of literal filename/filter format.

* clang-format.

---------

Co-authored-by: Tobias <thm.frey@gmail.com>

src/yuzu/main.ui

@@ -165,8 +165,9 @@
      <addaction name="separator"/>
      <addaction name="action_Configure_Tas"/>
     </widget>
-    <addaction name="action_Verify_installed_contents"/>
+    <addaction name="action_Install_Keys"/>
     <addaction name="action_Install_Firmware"/>
+    <addaction name="action_Verify_installed_contents"/>
     <addaction name="separator"/>
     <addaction name="menu_cabinet_applet"/>
     <addaction name="action_Load_Album"/>
@@ -469,6 +470,11 @@
     <string>Install Firmware</string>
    </property>
   </action>
+  <action name="action_Install_Keys">
+   <property name="text">
+    <string>Install Decryption Keys</string>
+   </property>
+  </action>
  </widget>
  <resources>
   <include location="yuzu.qrc"/>